.Net: Enhanced usage telemetry in SK

[markwallace-microsoft]

Add optional analytics to SK so we can track which models, vector stores and other features are being used

• First task is to identify how to implement this (which library etc.) and opt in
• Work with Shawn to create a plan for the additional telemetry we want to collect
• Create a task breakdown and work with Ben and Mark to distribute the work
• .Net: Add HTTP header for usage of Agent Framework  #10447